[gcc r12-2171] Use Object Size Type zero for -Warray-bounds [PR101374].

[Martin Sebor <msebor@gcc.gnu.org>]

https://gcc.gnu.org/g:9bf9f27ac6db4823628c435da9b242fd82bf8d68

commit r12-2171-g9bf9f27ac6db4823628c435da9b242fd82bf8d68
Author: Martin Sebor <msebor@redhat.com>
Date:   Thu Jul 8 11:34:27 2021 -0600

    Use Object Size Type zero for -Warray-bounds [PR101374].
    
    Resolves:
    PR bootstrap/101374 - -Warray-bounds accessing a member subobject as derived
    
    gcc/cp/ChangeLog:
            PR bootstrap/101374
            * module.cc (module_state::read_macro_maps): Temporarily disable
            -Warray-bounds.
            (module_state::install_macros): Same.
    
    gcc/ChangeLog:
            PR bootstrap/101374
            * gimple-array-bounds.cc (array_bounds_checker::check_mem_ref):
            Use Object Size Type 0 instead of 1.
    
    gcc/testsuite/ChangeLog:
            PR bootstrap/101374
            * c-c++-common/Warray-bounds-3.c: Xfail assertion.
            * c-c++-common/Warray-bounds-4.c: Same.

Diff:
---
 gcc/cp/module.cc                             | 13 +++++++++++++
 gcc/gimple-array-bounds.cc                   |  2 +-
 gcc/testsuite/c-c++-common/Warray-bounds-3.c |  2 +-
 gcc/testsuite/c-c++-common/Warray-bounds-4.c |  2 +-
 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index f259515a498..8a890c167cf 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -16301,11 +16301,18 @@ module_state::read_macro_maps ()
 	}
       if (count)
 	sec.set_overrun ();
+
+      /* FIXME: Re-enable or fix after root causing.  */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+
       dump (dumper::LOCATION)
 	&& dump ("Macro:%u %I %u/%u*2 locations [%u,%u)",
 		 ix, identifier (node), runs, n_tokens,
 		 MAP_START_LOCATION (macro),
 		 MAP_START_LOCATION (macro) + n_tokens);
+
+#pragma GCC diagnostic pop
     }
   location_t lwm = sec.u ();
   macro_locs.first = lwm - slurp->loc_deltas.second;
@@ -16911,6 +16918,10 @@ module_state::install_macros ()
       macro_import::slot &slot = imp.append (mod, flags);
       slot.offset = sec.u ();
 
+      /* FIXME: Re-enable or fix after root causing.  */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
+
       dump (dumper::MACRO)
 	&& dump ("Read %s macro %s%s%s %I at %u",
 		 imp.length () > 1 ? "add" : "new",
@@ -16931,6 +16942,8 @@ module_state::install_macros ()
 	    exp.def = cur;
 	    dump (dumper::MACRO)
 	      && dump ("Saving current #define %I", identifier (node));
+
+#pragma GCC diagnostic pop
 	  }
     }
 
diff --git a/gcc/gimple-array-bounds.cc b/gcc/gimple-array-bounds.cc
index 83b8db9755e..8dfd6f9500a 100644
--- a/gcc/gimple-array-bounds.cc
+++ b/gcc/gimple-array-bounds.cc
@@ -427,7 +427,7 @@ array_bounds_checker::check_mem_ref (location_t location, tree ref,
 	axssize = wi::to_offset (access_size);
 
   access_ref aref;
-  if (!compute_objsize (ref, 1, &aref, ranges))
+  if (!compute_objsize (ref, 0, &aref, ranges))
     return false;
 
   if (aref.offset_in_range (axssize))
diff --git a/gcc/testsuite/c-c++-common/Warray-bounds-3.c b/gcc/testsuite/c-c++-common/Warray-bounds-3.c
index 3d7c7687374..75f9a496eae 100644
--- a/gcc/testsuite/c-c++-common/Warray-bounds-3.c
+++ b/gcc/testsuite/c-c++-common/Warray-bounds-3.c
@@ -178,7 +178,7 @@ void test_memcpy_bounds_memarray_range (void)
 
   TM (ma.a5, ma.a5 + i, ma.a5, 1);
   TM (ma.a5, ma.a5 + i, ma.a5, 3);
-  TM (ma.a5, ma.a5 + i, ma.a5, 5);     /* { dg-warning "\\\[-Warray-bounds" } */
+  TM (ma.a5, ma.a5 + i, ma.a5, 5);     /* { dg-warning "\\\[-Warray-bounds" "pr101374" { xfail *-*-* } } */
   TM (ma.a5, ma.a5 + i, ma.a5, 7);     /* diagnosed with -Warray-bounds=2 */
 }
 
diff --git a/gcc/testsuite/c-c++-common/Warray-bounds-4.c b/gcc/testsuite/c-c++-common/Warray-bounds-4.c
index 1f73f11943f..835c634fd27 100644
--- a/gcc/testsuite/c-c++-common/Warray-bounds-4.c
+++ b/gcc/testsuite/c-c++-common/Warray-bounds-4.c
@@ -52,7 +52,7 @@ void test_memcpy_bounds_memarray_range (void)
          = MEM <unsigned char[5]> [(char * {ref-all})&ma];
      and could be improved.  Just verify that one is issued but not its
      full text.  */
-  TM (ma.a5, ma.a5 + j, ma.a5, 5);        /* { dg-warning "\\\[-Warray-bounds" } */
+  TM (ma.a5, ma.a5 + j, ma.a5, 5);        /* { dg-warning "\\\[-Warray-bounds" "pr101374" { xfail *-*-* } } */
 
   TM (ma.a5, ma.a5 + j, ma.a5, 7);        /* { dg-warning "offset \\\[5, 7] from the object at .ma. is out of the bounds of referenced subobject .\(MA::\)?a5. with type .char ?\\\[5]. at offset 0" } */
   TM (ma.a5, ma.a5 + j, ma.a5, 9);        /* { dg-warning "offset \\\[5, 9] from the object at .ma. is out of the bounds of referenced subobject .\(MA::\)?a5. with type .char ?\\\[5]. at offset 0" } */